Am i doing the right thing?

if i didnt trust my partner id feel the same and would be worried about something happening id never know about, but making him chose between you and a holiday is a bit far fetched. if hes going to cheat he will do it no matter where he is. work on your trust with him and go from there, if youre convinced he will cheat or he has cheated when he comes home then its your decision to end the relationship if you dont feel you trust him enough, but try and sort it beforehand itd be a shame to waste the relationship on paranoia and controlling what he can/cant do will make it worse. good luck.